The United Nationals General Assembly and the Human Rights Council declared access to sanitation and clean drinking water a human right in 2010.

The Sanitation Drive 2015 aims to end the lack of toilets in the world. This lack of access to toilets (even to pit latrines) results in what's called "open defecation" — pooping in fields, forests, bushes, and bodies of water.

It sounds barbaric, but 1.1 billion people on Earth have no other choice. This practice leads to deadly cases of diarrhea that kill more kids than AIDS, malaria, and measles combined, according to the UN [PDF]. When it doesn't kill, it keeps them out of school and makes them more likely to get other infections.

Not only does this practice spread disease and pollute environments and waterways, but it is also economically draining. Every dollar invested in sanitation development yields $5.50 in returns. For five reasons, according to the UN [PDF]:

Toilets increase national gross domestic product (GDP)

Toilets represent a business opportunity

Toilets reduce health costs

Toilets make education investments go further

Toilets protect water – clean water generates wealth

Toilets also keep girls in school longer, since currently many schools don't have private, separate facilities for girls and boys, which is a huge deal when women hit puberty and start menstruating.

Women are so embarrassed by openly defecating that they will sometimes wait until darkness to relieve themselves, which puts them at risk for sexual assault and rape.

To promote World Toilet Day, the World Health Organization has been tweeting and retweeting toilet pics under the hashtags #WorldToiletDay and #Toilets4All. Here are some good ones we've seen: